Abstract: Metrology targets are formed by a lithographic process, each target comprising a bottom grating and a top grating. Overlay performance of the lithographic process can be measured by illuminating each target with radiation and observing asymmetry in diffracted radiation. Parameters of metrology recipe and target design are selected so as to maximize accuracy of measurement of overlay, rather than reproducibility. The method includes calculating at least one of a relative amplitude and a relative phase between (i) a first radiation component representing radiation diffracted by the top grating and (ii) a second radiation component representing radiation diffracted by the bottom grating after traveling through the top grating and intervening layers. The top grating design may be modified to bring the relative amplitude close to unity. The wavelength of illuminating radiation in the metrology recipe can be adjusted to bring the relative phase close to ?/2 or 3?/2.

Abstract: A method of measuring a position of an alignment target on a substrate using an optical system. The method includes measuring a sub-segmented target by illuminating the sub-segmented target with radiation and detecting radiation diffracted by the sub-segmented target using a detector system to obtain signals containing positional information of the one sub-segmented target. The sub-segmented target has structures arranged periodically in at least a first direction, at least some of the structures including smaller sub-structures, and each sub-segmented target is formed with a positional offset between the structures and the sub-structures that is a combination of both known and unknown components. The signals, together with information on differences between known offsets of the sub-segmented target are used to calculate a measured position of an alignment target which is corrected for the unknown component of the positional offset.

Abstract: A method including: determining a value of a characteristic of a patterning process or a product thereof, at a current value of a processing parameter; determining whether a termination criterion is met by the value of the characteristic; if the termination criterion is not met, determining a new value of the processing parameter from the current value of the processing parameter and a prior value of the processing parameter, and setting the current value to the new value and repeating the determining steps; and if the termination criterion is met, providing the current value of the processing parameter as an approximation of a value of the processing parameter at which the characteristic has a target value.

Abstract: A method of determining an uncertainty in the position of a domain within a self-assembly block copolymer (BCP) feature. The method includes simulating a BCP feature, calculating a minimum energy position of a first domain within the simulated BCP feature, simulating the application of a potential that causes the position of the first domain to be displaced from the minimum energy position, simulating release of the potential back toward the minimum energy, recording a plurality of energies of the BCP feature during the release and recording at each of the plurality of energies a displacement of the first domain from the minimum energy position, calculating, from the recorded energies and recorded displacements, a probability distribution indicating a probability of the first domain being displaced from the minimum energy position, and, from the probability distribution, calculating an uncertainty in the position of the first domain within the BCP feature.

Abstract: An inspection apparatus comprises an illumination system (12) for illuminating a target structure with illuminating radiation and a collection system for collecting the illuminating radiation after it has been scattered by the target structure. A programmable spatial light modulator (713) comprises an array of movable mirror elements (742) in a conjugate pupil plane (P?) of the illumination system. Between the array of mirror elements and the target a common optical path is defined forming part of the illumination system and the collection system. Each mirror element is movable between a first position where it reflects illuminating radiation into the common optical path and a second position where it reflects radiation from the common optical path toward a detector (19, 23). Various combinations of illumination aperture and collection aperture can be defined without the light losses associated with beam splitters and transmissive spatial light modulators.

Abstract: Disclosed is an EUV system in which a source control loop is established to maintain and optimize debris flux while not unduly affecting optimum EUV generation conditions. One or more temperature sensors, e.g., thermocouples may be installed in the vessel to measure respective local gas temperatures. The respective local temperature as measured by the one or more thermocouples can be used as one or more inputs to the source control loop. The source control loop may then adjust the laser targeting to permit optimization of debris generation and deposition while not affecting EUV production, thus extending the lifetime of the source and its collector.

Abstract: Disclosed is a method of measuring a parameter of a lithographic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.

Abstract: A method including obtaining a plurality of radiation distributions of measurement radiation redirected by the target, each of the plurality of radiation distributions obtained at a different gap distance between the target and an optical element of a measurement apparatus, the optical element being the nearest optical element to the target used to provide the measurement radiation to the target, and determining a parameter related to the target using data of the plurality of radiation distributions in conjunction with a mathematical model describing the measurement target.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: A substrate holder for a lithographic apparatus has a planarization layer provided on a surface thereof. The planarization layer provides a smooth surface for the formation of a thin film stack forming an electronic component. The planarization layer is of substantially uniform thickness and/or its outer surface has a peak to valley distance of less than 10 ?m. The planarization layer may be formed by applying two solutions of different concentration. A surface treatment may be applied to the burls to repel a solution of the planarization layer material.

Abstract: Disclosed is an EUV system element having a hydrogen diffusion barrier including a region implanted with species (e.g., ions energetic neutral atoms) of a non-hydrogen gaseous material. Also disclosed is a method of making such a component including the step of implanting species of a non-hydrogen gaseous material to form a hydrogen diffusion barrier and a method of treating an EUV system element including the step of implanting species of a non-hydrogen gaseous material to prevent hydrogen adsorption and diffusion. Also disclosed is subjecting an EUV system element to a flux of non-hydrogen gas ions to displace hydrogen ions in one or more layers of the EUV system element with the non-hydrogen gas species so that the gas ions protect the EUV system element against hydrogen damage.

Abstract: A method for manufacturing a membrane assembly for EUV lithography, the method including: providing a stack including a membrane layer between a supporting substrate and an attachment substrate, wherein the supporting substrate includes an inner region and a border region; processing the stack, including selectively removing the inner region of the supporting substrate, to form a membrane assembly comprising: a membrane formed from at least the membrane layer; and a support holding the membrane, the support formed at least partially from the border region of the supporting substrate. The attachment substrate can be bonded to the rest of the stack.

Abstract: A method including measuring a value of a directly measureable processing parameter of a patterning process from a portion of a substrate produced by the patterning process; obtaining a relationship between the directly measureable processing parameter and a not directly measureable processing parameter; and determining a value of the not directly measureable processing parameter from the value of the directly measureable processing parameter and the relationship.

Abstract: Methods provide computationally efficient techniques for designing gauge patterns for calibrating a model for use in a simulation process. More specifically, the present invention relates to methods of designing gauge patterns that achieve complete coverage of parameter variations with minimum number of gauges and corresponding measurements in the calibration of a lithographic process utilized to image a target design having a plurality of features. According to some aspects, a method according to the invention includes transforming the space of model parametric space (based on CD sensitivity or Delta TCCs), then iteratively identifying the direction that is most orthogonal to existing gauges' CD sensitivities in this new space, and determining most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD changes along that direction in model parametric space.

Abstract: A method including modeling high resolution patterning error information of a patterning process involving a patterning device in a patterning system using an error mathematical model, modeling a correction of the patterning error that can be made by a patterning device modification tool using a correction mathematical model, the correction mathematical model having substantially the same resolution as the error mathematical model, and determining modification information for modifying the patterning device using the patterning device modification tool by applying the correction mathematical model to the patterning error information modeled by the error mathematical model.

Abstract: Methods and apparatus for measuring a parameter of interest of a target structure formed on substrate are disclosed. In one arrangement, the target structure comprises a first sub-target and a second sub-target. The first sub-target comprises a first bias and the second sub-target comprises a second bias. The method comprises determining the parameter of interest using a detected or estimated reference property of radiation at a first wavelength scattered from the first sub-target and a detected or estimated reference property of radiation at a second wavelength scattered from the second sub-target. The first wavelength is different to the second wavelength.

Abstract: A lithographic apparatus includes a clamp (406) configured to receive an object (402). The clamp defines at least one channel (408) configured to pass a fluid at a first fluid temperature. The lithographic apparatus also includes a chuck (404) coupled to the clamp. The chuck (404) defines at least one void (464) configured to thermally insulate the chuck from the clamp.

Abstract: An overlay metrology target (600, 900, 1000) contains a plurality of overlay gratings (932-935) formed by lithography. First diffraction signals (740(1)) are obtained from the target, and first asymmetry values (As) for the target structures are derived. Second diffraction signals (740(2)) are obtained from the target, and second asymmetry values (As?) are derived. The first and second diffraction signals are obtained using different capture conditions and/or different designs of target structures and/or bias values. The first asymmetry signals and the second asymmetry signals are used to solve equations and obtain a measurement of overlay error. The calculation of overlay error makes no assumption whether asymmetry in a given target structure results from overlay in the first direction, in a second direction or in both directions. With a suitable bias scheme the method allows overlay and other asymmetry-related properties to be measured accurately, even in the presence of two-dimensional overlay structure.

Abstract: A route for a substrate support that supports a substrate in an immersion lithographic apparatus is calculated to satisfy the following constraints: after the edge of the substrate first contacts the immersion space, the substrate remains in contact with the immersion space until all target portions are exposed; exposures of target portions are performed while the substrate moves in a scan direction; and all movements of the substrate between exposures are, in a plane parallel to its upper surface, either curved or only in one of the scan directions or transverse directions. In order to reduce exposure defects at the edge of the substrate the outside portion of the substrate is avoided from being exposed to the immersion liquid. The transfer routes are designed to overly the substrate surface.

Abstract: A method of determining a patterning process parameter from a metrology target, the method including: obtaining a plurality of values of diffraction radiation from the metrology target, each value of the plurality of values corresponding to a different illumination condition of a plurality of illumination conditions of illumination radiation for the target; and using the combination of values to determine a same value of the patterning process parameter for the target.